Which characteristic is associated with graphite materials?

Graphite materials are well-known for their ultra-high stiffness. This characteristic is due to their unique layered structure and strong covalent bonding within the layers, which provides significant resistance to deformation under loads. The strength and stiffness of graphite make it an excellent material for applications that require high performance under mechanical stress.

In contrast, while graphite can be lightweight, it's important to note that low density is more closely associated with other materials like aluminum or plastics compared to graphite. Additionally, although graphite does exhibit good electrical conductivity, the emphasis on stiffness aligns more specifically with its structural applications. High thermal expansion is also not a defining property of graphite; rather, many materials utilized in similar contexts have different thermal characteristics. Overall, the ultra-high stiffness characteristic is the most accurate in describing what sets graphite apart, particularly in structural applications.